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CX2SA > SATDIG 09.02.10 22:12l 859 Lines 29953 Bytes #999 (0) @ WW
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Today's Topics:
1. Good Night, Loran (Clint BRADFORD)
2. Re: New Lindy's QRV (Bill Dzurilla)
3. Re: Good Night, Loran (w6zkh@xxxxxxx.xxxx
4. AO-51 Signal Strength Post Flip (John Papay)
5. Re: Good Night, Loran (tosca005@xxx.xxxx
6. Re: New Lindy's QRV (Mark Spencer)
7. Re: AO-51 Signal Strength Post Flip (Mark L. Hammond)
8. Re: AO-51 Signal Strength Post Flip (Mark L. Hammond)
9. Re: Good Night, Loran (Gordon JC Pearce)
10. Re: AO-51 Signal Strength Post Flip (B J)
11. Re: AO-51 Signal Strength Post Flip (Mark L. Hammond)
12. Re: New Lindy's QRV (Edward Cole)
13. Re: AO-51 Signal Strength Post Flip (Elan Portnoy)
----------------------------------------------------------------------
Message: 1
Date: Tue, 09 Feb 2010 03:36:58 -0800
From: Clint BRADFORD <clintbradford@xxx.xxx>
Subject: [amsat-bb] Good Night, Loran
To: amsat-bb@xxxxx.xxx
Message-ID: <28A5D030-4D44-4F14-BBCE-9416E23A4F7A@xxx.xxx>
Content-Type: text/plain; charset=us-ascii
In a series of small ceremonies, the U.S. Coast Guard on Monday shut down
Loran-C, a navigation and timing system that has guided mariners and
aviators since World War II.
The death blow came last May when President Obama called the system
obsolete, saying it is no longer needed in an age in which Global
Positioning System devices are nearly ubiquitous in cars, planes and boats.
Killing Loran-C will save the government $190 million over five years, Obama
said. But supporters of Loran -- including the man known as "the father of
GPS" -- say the nation's increasing reliance on GPS paradoxically has
increased the importance of maintaining Loran as a backup.
At 3 p.m. Monday, the U.S. Coast Guard turned off Loran signals at 19 of the
24 Loran stations. Signals remain at five stations because of agreements
with Russia and Canada, but the Coast Guard expects those stations to be
decommissioned by June after the United States receives verification that
those countries have been notified of the change.
The five stations that temporarily remain on line are at Attu, in Alaska's
Aleutian Islands, and Caribou, Maine; Nantucket, Massachusetts; Shoal Cove,
Alaska; and George, Washington.
- from CNN/Reuters
Clint Bradford, K6LCS
------------------------------
Message: 2
Date: Tue, 9 Feb 2010 06:23:18 -0800 (PST)
From: Bill Dzurilla <billdz.geo@xxxxx.xxx>
Subject: [amsat-bb] Re: New Lindy's QRV
To: amsat-bb@xxxxx.xxx
Message-ID: <164124.25094.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
Dave,
I would be suspicious of the construction. I can get a few minutes of good
copy from AO-51 on a high pass with just a rubber duck on an HT. If you do
get a preamp, the run between the antenna and the preamp is critical, so if
possible keep it short and use good coax. Ed seems to be having success
with 4' of RG-58U, but generally the use of any RG-58U at 70cm is not a good
idea.
Here's a quick summary of my results with various antennas:
* HT and rubber duck or other antenna mounted directly on the HT - success
only at high elevations
* HT and Arrow or Elk antenna, no preamp - success from horizon to horizon,
if no trees or other obstructions
* base rig and dual band omnidirectional ground plane, no preamp, 40' of
RG-213U - success on most birds only when elevation is above 25-35 degrees
* base rig and dual band omnidirectional ground plane, ARR preamp, 40' of
RG-213U - success on most birds when elevation is above 15 degrees
* base rig and Elk antenna on 12' pole at 15 degrees fixed elevation,
azimuth rotation with old TV antenna rotor, ARR preamp, 70' coax run (my
current setup) - full success from horizon to horizon on all birds, except
in directions where blocked by trees or roof.
The Elk is $135 shipped and the used rotor was $25, and this combo is by far
the most effective I have used. My community has antenna restrictions, but
so far no one has complained about the little 2' long Elk. The Elk could be
replaced with a homebrew Cheap Yagi or tape measure yagi, which can be built
for $10.
I am not aware of anyone who is able to work the sats at low elevations with
any type of omnidirectional antenna, even with the best preamp. You can
have plenty of fun working the birds at higher elevations, but you will be
able to work more passes and better DX (e.g., Europe on AO-7) if you can
catch them at lower elevations.
73, Bill NZ5N
> Date: Mon, 08 Feb 2010 17:26:11 -0700
> From: David Ek <dave@xxxxxxxx.xxx>
> Subject: [amsat-bb] Re: New Lindy's QRV
> To: amsat-bb@xxxxx.xxx
> Message-ID: <4B70ABA3.9090908@xxxxxxxx.xxx>
> Content-Type: text/plain; charset=ISO-8859-1;
> format=flowed
>
> Question for anyone out there: I just built the parasitic
> Lindy from the
> Feb 2010 QST. What kind of performance (on receive) should
> I expect from
> it during, say, an AO-51 pass (max EL 83 deg)? I had my
> Kenwood TH-F6a
> HT connected directly to it (only a few feet of RG-8X coax
> to the
> antenna) with no preamp, and I only had good copy for a
> moment here and
> there. Just wondering if I need a preamp or if I need to be
> suspicious
> of my construction.
>
> tnx & 73,
>
> Dave NK0E
>
> -----------------
>
> Edward Cole wrote:
> I forgot to add that these are patterned after Tony, AA2TX,
> designs
> (UHF version is in Feb. 2010 QST).
> My variation was to use pvc sched-40 plastic pipe (white).
>
> The preamp is one of the older DEMI designs that uses a
> mgf-1302
> GasFet with about 0.7 dBNF.? I see about one s-unit of
> noise when I
> turn it on.? There is 4-feet of RG-58 to the UHF Lindy
> and 60-feet to
> the FT-847 from the preamp.? The VHF Lindy has no
> preamp and is fed
> with 60-feet of RG-213.
>
> The VHF Lindy brings up repeaters 70-miles away with 50w,
> and the UHF
> Lindy hears repeaters that far away.? So actually can
> make a nice
> general purpose antenna.
>
> 73, Ed
>
------------------------------
Message: 3
Date: Tue, 9 Feb 2010 15:28:21 +0000 (UTC)
From: w6zkh@xxxxxxx.xxx
Subject: [amsat-bb] Re: Good Night, Loran
To: Clint BRADFORD <clintbradford@xxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID:
<1628563812.1890331265729301136.JavaMail.root@xxxxxxx.xxxxxxxxxxx.xx.xxxx.xxxx
xxx.xxx>
Content-Type: text/plain; charset=utf-8
In our aging fleet of GPS Satellites, which are on the brink of dying, and
no replacements in sight, wonder what will happen then?? Everyone dont throw
away your compass and paper maps. $190 mill is a small price to pay for
something that will work, compared to what other $$ the govt throws away on
toilet seats, etc.
John W6ZKH
----- Original Message -----
From: "Clint BRADFORD" <clintbradford@xxx.xxx>
To: amsat-bb@xxxxx.xxx
Sent: Tuesday, February 9, 2010 3:36:58 AM GMT -08:00 US/Canada Pacific
Subject: [amsat-bb] Good Night, Loran
In a series of small ceremonies, the U.S. Coast Guard on Monday shut down
Loran-C, a navigation and timing system that has guided mariners and
aviators since World War II.
The death blow came last May when President Obama called the system
obsolete, saying it is no longer needed in an age in which Global
Positioning System devices are nearly ubiquitous in cars, planes and boats.
Killing Loran-C will save the government $190 million over five years, Obama
said. But supporters of Loran -- including the man known as "the father of
GPS" -- say the nation's increasing reliance on GPS paradoxically has
increased the importance of maintaining Loran as a backup.
At 3 p.m. Monday, the U.S. Coast Guard turned off Loran signals at 19 of the
24 Loran stations. Signals remain at five stations because of agreements
with Russia and Canada, but the Coast Guard expects those stations to be
decommissioned by June after the United States receives verification that
those countries have been notified of the change.
The five stations that temporarily remain on line are at Attu, in Alaska's
Aleutian Islands, and Caribou, Maine; Nantucket, Massachusetts; Shoal Cove,
Alaska; and George, Washington.
- from CNN/Reuters
Clint Bradford, K6LCS
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 4
Date: Tue, 09 Feb 2010 10:47:54 -0500
From: John Papay <john@xxxxxx.xxx>
Subject: [amsat-bb] AO-51 Signal Strength Post Flip
To: amsat-bb@xxxxx.xxx
Message-ID: <114697.17832.qm@xxxxxxx.xxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
It has been about a month now since AO-51 was commanded back to
its normal orientation. But many are reporting that they are having more
trouble hearing it now than they did before the first re-orientation.
It does seem to me that some stations that usually hear very well are not
hearing that well now. This morning's pass (9Feb2010 1045z) of AO-51
seemed to bear that out. AF6RF, KB1RVT, KE3LB, WD0X?, KJ4CBC,
K5QXJ, WB2IOL and YF6BFE were on the pass and with a few
exceptions, all were not able to hear at some point during the pass.
There are also a few noisy uplink transmissions as well.
The recording can be downloaded at:
http://www.papays.com/AO-51_09Feb2010_104452za.mp3
(there are no signals in the first minute of the recording)
Is anyone else having trouble hearing AO-51 as well as they heard it before
the flip experiment?
73,
John K8YSE
------------------------------
Message: 5
Date: 09 Feb 2010 09:52:18 -0600
From: tosca005@xxx.xxx
Subject: [amsat-bb] Re: Good Night, Loran
To: amsat-bb@xxxxx.xxx
Message-ID: <Gophermail.2.0.1002090952180.22440@xxxx.xx.xxx.xxx>
Content-Type: text/plain; format=flowed; charset=UTF-8
Does the US government NOT have any plans to launch any more GPS satellites?
Does the existing array of satellites in orbit have any which are not in
active use, i.e. reserved for future use as backups? As I recall, each
satellite has two different atomic standards on board, one is on and the
other is off (or is it 3 independent standards, one rubidium and two of
something else?). So, how many spare atomic standards on functional
satellites do we have to keep the aging fleet going?
What is the cost of a GPS satellite launch vs. the cost savings of killing
off Loran-C?
Sorry if your comments triggered more questions than answers from me...
73 de W0JT
On Feb 9 2010, w6zkh@xxxxxxx.xxx wrote:
> In our aging fleet of GPS Satellites, which are on the brink of dying,
> and no replacements in sight, wonder what will happen then??
>...
>John W6ZKH
>
>
>----- Original Message -----
>From: "Clint BRADFORD" <clintbradford@xxx.xxx>
>To: amsat-bb@xxxxx.xxx
>Sent: Tuesday, February 9, 2010 3:36:58 AM GMT -08:00 US/Canada Pacific
>Subject: [amsat-bb] Good Night, Loran
>
> In a series of small ceremonies, the U.S. Coast Guard on Monday shut down
> Loran-C, a navigation and timing system that has guided mariners and
> aviators since World War II.
...
>
>Clint Bradford, K6LCS
------------------------------
Message: 6
Date: Tue, 9 Feb 2010 08:41:57 -0800 (PST)
From: Mark Spencer <mspencer12345@xxxxx.xx>
Subject: [amsat-bb] Re: New Lindy's QRV
To: amsat-bb@xxxxx.xxx
Message-ID: <108787.8421.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
I can consistently copy the beacons on FO 29 and HO 68 down to the horizion
using a larsen 2/70 mobile antenna with the larsen radial kit.?? The feed
line is approx 60 feet of Belden 9913F.??? I typically connect the antenna
to a comet duplexer to?my mirage UHF amplifer which has a gasfet preamp and
use my??FT736 as a receiver, but the 736 can copy the beacons with the
preamp switched off.??I have an ARR gasfet preamp that works a bit better
but is not TR switched and I usually don't bother with it.?? VO52 is also
typically copyable down to the horizon with this setup.??
I haven't been on the FM sats in a while but don't recall any issues copying
them either.??
I have been told by several people that my ears seem to do a?better job than
others at copying weak signals though (:
----- Original Message ----
From: Bill Dzurilla <billdz.geo@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Sent: Tue, February 9, 2010 6:23:18 AM
Subject: [amsat-bb] Re: New Lindy's QRV
Dave,
I would be suspicious of the construction.? I can get a few minutes of good
copy from AO-51 on a high pass with just a rubber duck on an HT.? If you do
get a preamp, the run between the antenna and the preamp is critical, so if
possible keep it short and use good coax.? Ed seems to be having success
with 4' of RG-58U, but generally the use of any RG-58U at 70cm is not a good
idea.
Here's a quick summary of my results with various antennas:
* HT and rubber duck or other antenna mounted directly on the HT - success
only at high elevations
* HT and Arrow or Elk antenna, no preamp - success from horizon to horizon,
if no trees or other obstructions
* base rig and dual band omnidirectional ground plane, no preamp, 40' of
RG-213U - success on most birds only when elevation is above 25-35 degrees
* base rig and dual band omnidirectional ground plane, ARR preamp, 40' of
RG-213U - success on most birds when elevation is above 15 degrees
* base rig and Elk antenna on 12' pole at 15 degrees fixed elevation,
azimuth rotation with old TV antenna rotor, ARR preamp, 70' coax run (my
current setup) - full success from horizon to horizon on all birds, except
in directions where blocked by trees or roof.
The Elk is $135 shipped and the used rotor was $25, and this combo is by far
the most effective I have used.? My community has antenna restrictions, but
so far no one has complained about the little 2' long Elk.? The Elk could be
replaced with a homebrew Cheap Yagi or tape measure yagi, which can be built
for $10.
I am not aware of anyone who is able to work the sats at low elevations with
any type of omnidirectional antenna, even with the best preamp.? You can
have plenty of fun working the birds at higher elevations, but you will be
able to work more passes and better DX (e.g., Europe on AO-7) if you can
catch them at lower elevations.
73, Bill NZ5N?
__________________________________________________________________
Looking for the perfect gift? Give the gift of Flickr!
http://www.flickr.com/gift/
------------------------------
Message: 7
Date: Tue, 9 Feb 2010 12:35:35 -0500
From: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
Subject: [amsat-bb] Re: AO-51 Signal Strength Post Flip
To: John Papay <john@xxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID:
<5d8cecfe1002090935n2ff474b8jb5791d49b8a424c7@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Hi John,
Have you looked to see what power levels we were running at the
comparision times? Maybe that's part of it...
The orientation should be "back to the way it was" before the flip
experiments. What might be differnet is power budget and therefore
signal strength.
Anyhow, it's good to ask and compare notes!
73,
Mark
On Tue, Feb 9, 2010 at 10:47 AM, John Papay <john@xxxxxx.xxx> wrote:
> It ?has been about a month now since AO-51 was commanded back to
> its normal orientation. ?But many are reporting that they are having more
> trouble hearing it now than they did before the first re-orientation.
>
> It does seem to me that some stations that usually hear very well are not
> hearing that well now. ?This morning's pass (9Feb2010 1045z) of AO-51
> seemed to bear that out. ?AF6RF, KB1RVT, KE3LB, WD0X?, KJ4CBC,
> K5QXJ, WB2IOL and YF6BFE were on the pass and with a few
> exceptions, all were not able to hear at some point during the pass.
> There are also a few noisy uplink transmissions as well.
>
> The recording can be downloaded at:
> http://www.papays.com/AO-51_09Feb2010_104452za.mp3
> (there are no signals in the first minute of the recording)
>
> Is anyone else having trouble hearing AO-51 as well as they heard it before
> the flip experiment?
>
> 73,
> John K8YSE
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
--
Mark L. Hammond [N8MH]
------------------------------
Message: 8
Date: Tue, 9 Feb 2010 12:42:25 -0500
From: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
Subject: [amsat-bb] Re: AO-51 Signal Strength Post Flip
To: John Papay <john@xxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID:
<5d8cecfe1002090942y35cf7c28u26f0ecd00803b69c@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
By the way, John--a handy place to spot check power levels at various
dates is here:
http://www.amsat.dk/oz7sat/tlm/view.php?sat=ao51 Just put in the
dates you want to see.
And the full telemetry archive is on the AMSAT FTP server, so folks
can grab, decode, and and analyze anything they want, for any
telemetry that's been collected.
73,
Mark N8MH
On Tue, Feb 9, 2010 at 12:35 PM, Mark L. Hammond <marklhammond@xxxxx.xxx>
wrote:
> Hi John,
>
> Have you looked to see what power levels we were running at the
> comparision times? ?Maybe that's part of it...
>
> The orientation should be "back to the way it was" before the flip
> experiments. ?What might be differnet is power budget and therefore
> signal strength.
>
> Anyhow, it's good to ask and compare notes!
>
> 73,
>
> Mark
>
> On Tue, Feb 9, 2010 at 10:47 AM, John Papay <john@xxxxxx.xxx> wrote:
>> It ?has been about a month now since AO-51 was commanded back to
>> its normal orientation. ?But many are reporting that they are having more
>> trouble hearing it now than they did before the first re-orientation.
>>
>> It does seem to me that some stations that usually hear very well are not
>> hearing that well now. ?This morning's pass (9Feb2010 1045z) of AO-51
>> seemed to bear that out. ?AF6RF, KB1RVT, KE3LB, WD0X?, KJ4CBC,
>> K5QXJ, WB2IOL and YF6BFE were on the pass and with a few
>> exceptions, all were not able to hear at some point during the pass.
>> There are also a few noisy uplink transmissions as well.
>>
>> The recording can be downloaded at:
>> http://www.papays.com/AO-51_09Feb2010_104452za.mp3
>> (there are no signals in the first minute of the recording)
>>
>> Is anyone else having trouble hearing AO-51 as well as they heard it before
>> the flip experiment?
>>
>> 73,
>> John K8YSE
>>
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>
>
>
> --
> Mark L. Hammond [N8MH]
>
--
Mark L. Hammond [N8MH]
------------------------------
Message: 9
Date: Tue, 09 Feb 2010 17:56:35 +0000
From: Gordon JC Pearce <gordonjcp@xxxx.xxx>
Subject: [amsat-bb] Re: Good Night, Loran
To: amsat-bb@xxxxx.xxx
Message-ID: <1265738195.3834.4.camel@xxxxx.xxxx>
Content-Type: text/plain; charset="UTF-8"
On Tue, 2010-02-09 at 09:52 -0600, tosca005@xxx.xxx wrote:
> Does the US government NOT have any plans to launch any more GPS satellites?
Nope.
Keep cheering on the Iranians and their space-flight programme. They'll
be the only game in town ten years from now, if things keep on like
this.
You might even get a HEO launch out of them.
Gordon MM0YEQ
------------------------------
Message: 10
Date: Tue, 9 Feb 2010 10:00:31 -0800 (PST)
From: B J <top_gun_canada@xxxxx.xxx>
Subject: [amsat-bb] Re: AO-51 Signal Strength Post Flip
To: John Papay <john@xxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <730389.23444.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
--- On Tue, 2/9/10, John Papay <john@xxxxxx.xxx> wrote:
> From: John Papay <john@xxxxxx.xxx>
> Subject: [amsat-bb] AO-51 Signal Strength Post Flip
> To: amsat-bb@xxxxx.xxx
> Received: Tuesday, February 9, 2010, 8:47 AM
> It has been about a month now
> since AO-51 was commanded back to
> its normal orientation. But many are reporting that
> they are having more
> trouble hearing it now than they did before the first
> re-orientation.
>
> It does seem to me that some stations that usually hear
> very well are not
> hearing that well now. This morning's pass (9Feb2010
> 1045z) of AO-51
> seemed to bear that out. AF6RF, KB1RVT, KE3LB, WD0X?,
> KJ4CBC,
> K5QXJ, WB2IOL and YF6BFE were on the pass and with a few
> exceptions, all were not able to hear at some point during
> the pass.
> There are also a few noisy uplink transmissions as well.
>
> The recording can be downloaded at:
> http://www.papays.com/AO-51_09Feb2010_104452za.mp3
> (there are no signals in the first minute of the
> recording)
>
> Is anyone else having trouble hearing AO-51 as well as they
> heard it before
> the flip experiment?
<snip>
In the past few weeks, I've often had problems hearing AO-51 here in DO33.
A year ago, signals of at least S3 on my FT-817ND were common. Now they are
weaker.
As well, I get the impression that the signal polarity has changed.
Formerly, I could hold my Arrow dual-band Yagi with the 2 m elements nearly
horizontal and still hear the satellite. Now, I have to turn it nearly 90
degrees, sometimes changing the orientation more than once during a pass.
Some of that I might attribute to my operating a portable station within a
residential area in the city, but I definitely noticed a significant
difference between what I hear from AO-51 now and what it was before the
satellite was flipped.
73s
Bernhard VA6BMJ @ DO33FL
__________________________________________________________________
Yahoo! Canada Toolbar: Search from anywhere on the web, and bookmark your
favourite sites. Download it now
http://ca.toolbar.yahoo.com.
------------------------------
Message: 11
Date: Tue, 9 Feb 2010 13:41:44 -0500
From: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
Subject: [amsat-bb] Re: AO-51 Signal Strength Post Flip
To: B J <top_gun_canada@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxxx John Papay <john@xxxxxx.xxx>
Message-ID:
<5d8cecfe1002091041i26b04013y3c72ad80a2de40a4@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Thanks for the reports.
Again, I encourage you all to research the power levels OUT at the
comparison times. That has to at least be considered in the
discussion.
For example:
Power is "watts" out
Date 435.150 435.300 Battery V
Before flips
2009-02-09 19:27:04 oz7sat 0 0.779 0.859 7.660 <--- 859 mW one
year ago! compare to today, listed below!
2009-10-25 18:17:01 oz7sat 0 0.452 0.617 7.868
2009-11-25 17:41:51 oz7sat 0 0.361 0.744 7.581 <-- 745 mW before the flip!
2010-01-15 18:45:31 oz7sat 0 0.437 0.462 7.892
Currently:
2010-02-09 17:19:06 oz7sat 0 0.452 0.475 7.752 <-- 475 mW today!
We are running a few hundred milliwatts below what we were running
pre-flip, and a good bit less than we were able to run a year ago.
So you all may be seeing the difference between 600-850 mW and 475 mW.
It's real.
Yes, the bird is aging, and we're doing the best we can to manage the
resources available on-board (the limits now are orbit and battery
condition) . The full illumination periods in the last year or two
have taken their toll on the batteries. What will be interesting is
to see what happens when we return to periods of eclipse!!
Personally, I don't expect the situatio to improve, although it might
be that the batteries will cool and some capacity will return. But
we'll need it with eclipses.
73,
Mark N8MH
>
> In the past few weeks, I've often had problems hearing AO-51 here in DO33.
?A year ago, signals of at least S3 on my FT-817ND were common. ?Now they
are weaker.
>
> As well, I get the impression that the signal polarity has changed.
?Formerly, I could hold my Arrow dual-band Yagi with the 2 m elements nearly
horizontal and still hear the satellite. ?Now, I have to turn it nearly 90
degrees, sometimes changing the orientation more than once during a pass.
>
> Some of that I might attribute to my operating a portable station within a
?residential area in the city, but I definitely noticed a significant
difference between what I hear from AO-51 now and what it was before the
satellite was flipped.
>
> 73s
>
> Bernhard VA6BMJ @ DO33FL
>
>
>
> ? ? ?__________________________________________________________________
> Yahoo! Canada Toolbar: Search from anywhere on the web, and bookmark your
favourite sites. Download it now
> http://ca.toolbar.yahoo.com.
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
--
Mark L. Hammond [N8MH]
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Message: 12
Date: Tue, 09 Feb 2010 10:08:01 -0900
From: Edward Cole <kl7uw@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: New Lindy's QRV
To: amsat-bb@xxxxx.xxx
Message-ID: <201002091908.o19J81NC003445@xxxxxxx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
At 05:23 AM 2/9/2010, Bill Dzurilla wrote:
>Dave,
>
>I would be suspicious of the construction. I can get a few minutes
>of good copy from AO-51 on a high pass with just a rubber duck on an
>HT. If you do get a preamp, the run between the antenna and the
>preamp is critical, so if possible keep it short and use good
>coax. Ed seems to be having success with 4' of RG-58U, but
>generally the use of any RG-58U at 70cm is not a good idea.
Agreed in general, but if you look at the antenna it requires small
diameter coax. Loss at 450-MHz for RG-58 is around 9-10 dB (I didn't
look it up so used the loss for RG-223). So for 4/100 feet the loss
is 0.4 dB. This adds to the preamp 0.7 dB NF so it is not optimum,
but a lot better than the typical 432 ham receiver that is, at best,
6 dB NF. My FT-847 with internal preamp on is 12 dB NF, so reduction
to 1.1 dB is a good improvement. The cable length is for convenience
and could be made shorter.
Using better coax from the preamp to the shack would also be
better. I used 60-feet of RG-58, because I am "cheap". yet, it
seems to be working pretty good.
When I get the connections completed on my tracking array, I can
compare it with my 0.5 dB NF preamp and 436CP42. The latter is lower
to the ground so may encounter some ground clutter limiting tracking
to zero elevation. Let you all know when I get it QRV. When I had
it roof -mounted at the old qth, I could track AO-27 down to a few degrees.
>Here's a quick summary of my results with various antennas:
>
>* HT and rubber duck or other antenna mounted directly on the HT -
>success only at high elevations
>* HT and Arrow or Elk antenna, no preamp - success from horizon to
>horizon, if no trees or other obstructions
>* base rig and dual band omnidirectional ground plane, no preamp,
>40' of RG-213U - success on most birds only when elevation is above
>25-35 degrees
>* base rig and dual band omnidirectional ground plane, ARR preamp,
>40' of RG-213U - success on most birds when elevation is above 15 degrees
So far, with the Lindy+4 feet RG-58+preamp I am seeing good signals
to and a little below 10-degrees.
>* base rig and Elk antenna on 12' pole at 15 degrees fixed
>elevation, azimuth rotation with old TV antenna rotor, ARR preamp,
>70' coax run (my current setup) - full success from horizon to
>horizon on all birds, except in directions where blocked by trees or roof.
>
>The Elk is $135 shipped and the used rotor was $25, and this combo
>is by far the most effective I have used. My community has antenna
>restrictions, but so far no one has complained about the little 2'
>long Elk. The Elk could be replaced with a homebrew Cheap Yagi or
>tape measure yagi, which can be built for $10.
>
>I am not aware of anyone who is able to work the sats at low
>elevations with any type of omnidirectional antenna, even with the
>best preamp. You can have plenty of fun working the birds at higher
>elevations, but you will be able to work more passes and better DX
>(e.g., Europe on AO-7) if you can catch them at lower elevations.
That is why my Lindy is set up only for the typ. mode VU FM birds. I
will use the better directional antennas for the linear birds (when I
get them connected).
>73, Bill NZ5N
73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
500-KHz/CW, 144-MHz EME, 1296-MHz EME
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Message: 13
Date: Tue, 9 Feb 2010 11:48:03 -0800 (PST)
From: Elan Portnoy <elanportnoy@xxxxx.xxx>
Subject: [amsat-bb] Re: AO-51 Signal Strength Post Flip
To: amsat-bb@xxxxx.xxx
Message-ID: <741703.90750.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
You are on-the-nose John.
Currently, I AOS and LOS AO-51 at higher elevations than before the initial
flip. During high passes, the downlink is no longer DFQ or is as strong as
before, and there are more fades (was better with leaves still on the trees!).
I have questioned my antenna calibration; it appears to be where it was
previously. Clock, Keps, etc., all good too.
So that's my observation--jives with John's. Of course I am appreciative of
the team keeping her chugging, but feedback is helpful I'm sure.
73,
Elan WB2IOL
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